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How do Seagull and Hangzhou compare to a ETA: An in-depth look...

306944 Views 121 Replies 63 Participants Last post by  johnmichael
I was asked to do a review and comparison of two Chinese movements, the Seagull TY2130 and Hangzhou HZ6300, the two movements were provided by Carlos of the Prometheus Watch Company. These two movements would be compared against the ubiquitous Standard grade ETA 2824-2 and a Top grade ETA 2004-1

I originally planned to do all my testing and tear down first then post the results, however with four movements, there was too much information for one initial post. So I am now going to do a running commentary of the test, disassembly and comparison as I finish each phase.

Right now, I have four parts in this study, 1) Description & Initial Timing, 2) Tear-down and Comparison of Quality, 3) Interchangeability, and 4) Assessment.

This will allow for comments to be posted after each part.

Part one: Description and Initial timing tests.

Seagull TY2130

Hangzhou HZ6300

ETA 2824-2 (Rado)

TY2130, HZ6300 and ETA 2824-2
Type: Automatic mechanical lever movement
Size: 25.60 mm (26.00 mm overall) x 4.60 mm
Frequency: 4 Hz (28,800 bph)
Analog three hand display with quick change date, three position winding/setting stem.
The ETA is a Standard grade with a gold plated nickel balance and Nivarox 2 balance spring, I do not know what material the Seagull and Hangzhou are using.

ETA 2004-1

ETA 2004-1
Type: Automatic mechanical lever movement (uni-directional winding)
Size: 23.30 mm (23.90 mm overall) x 3.60 mm
Frequency: 4 Hz (28,800 bph)
Analog three hand display with quick change date, three position winding/setting stem.
This is a Top grade ETA with a gold plated Glucydur balance and Anachron balance spring

The TY2130 and the HZ6300 were taken directly from the package, wound and placed on a Mumford MicroSet Watch Timer. Then after running (movements motionless) for 24 hours, the rate (CH only) was taken again to establish the Isochronism.

The initial results were as follows:

Beat error: 0.3 ms
Rate, CH (dial up): -4.8 seconds per day
Rate, 9H (crown down): +0.6 s/d
Isochronism: +9.6 s/d

Beat error: 0.1 ms
Rate, CH: +15.2 s/d
Rate, 9H: +11.7 s/d
Isochronism: -3.5 s/d

ETA 2824-2 (Rado, recently serviced):
Beat error: 0.2 ms
Rate, CH: +2.7 s/d
Rate, 9H: +2.0 s/d
Isochronism: -8.2 s/d

ETA 2004-1 (loose, recently serviced):
Beat error: 0.0 ms
Rate, CH: +3.4 s/d
Rate, 9H: -3.4 s/d
Isochronism: -7.5 s/d

All the movements showed excellent rate stability and amplitude (around 310 degrees for the 2824s and 300 degrees for the 2004) over the 24 hours they were under test.

Just for comparison, the specifications from ETA for the two movements are as follows:

ETA 2824-2 (Standard grade)
Rate: +/- 12 s/d
Variation between all positions: 30 s/d
Isochronism: +/- 20 s/d
Amplitude: maximum 315 to 325 degrees; minimum 200 to 220 degrees

ETA 2004-1 (Top grade)
Rate: +/- 7 s/d
Variation between all positions: 30 s/d
Isochronism: +/- 25 s/d
Amplitude: maximum 310 degrees; minimum 190 degrees

So, we can see that the two TY2130 and HZ6300 samples, in the "as received" condition, are quite capable of meeting ETA minimum specifications, and show very good performance in the two positions tested.

Note on the finish of the movements, The Rado ETA 2824-2 is plain gold plate with a very simple pattern on the rotor, the HZ6300 is plain nickel plate with absolutely no decoration. The TY2130 is finished in a manner similar to the ETA 2004-1 with a fine nickel plate and pearlage on the visible plates and Cote-de-Geneve on the rotor. From a strict utilitarian point of view, nickel plating is the best finish, but is slightly more expensive than gold plate due to the cost of handling the chemical waste associated with nickel plating. Also, pearlage and other decorations show up better on nickel plating.

Stay tuned for part two...
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Excellent review, and one that I am sure we are all waiting for. Personally I think the Sea-Gull ST2130 is great. I have used both the ST2130 and the 6300 in projects and watches I have sold no Sea-Gulls have come back - so that should say something for the quality.

I am waiting for the next instalment. Good one

My personal preference is the Sea-Gull. I have a lot of vintage Sea-Gulls and will be buying some ST2130's in the new year.
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Good stuff :-!

I think your findings through the 4 stages will give Carlos enough ammo to use the Chinese movements with confidence, so long as he can source them from a reputable source...unlike the recent batch he had to turf.

I await the next installments with baited breath :-d
It's kinda funny to my untrained eye, the ETA 2004 looks like the cheapist one of the lot. With it's small balance wheel and "calvin klien" on the rotor lol
I seem to have forgotten an image of the back of the Hangzhou. I have edited the post to add the missing image.

The ETA 2004-1 is a small movement, 10-1/2 lignes, but the base movement is the even smaller ETA 2000-1, an 8-3/4 ligne movement. You may note the large amount of "dead-space" outside of the bridge plates.

The ETA 2004 and 2000 are easily on par with their bigger cousin the ETA 2892A2, which is why I chose it, not having a spare 2892A2 to play with.

"Calvin Klein" just proves that some fashion watches have very good movements it them, although it may not totally justify the price tag.

Next installment will be tomorrow, g'night all.
Fantastic start. I look forward to your continuation!
Part two: a) Tear-down.

The disassembly of the TY2130 and the HZ6300 is straight forward, and thanks to the design, there aren't many little springs to go flying (only one, in fact, the click spring, all of the other springs are integral with a larger part). This part will just show pictures the teardown of one sample, as two of the others will be the same and the teardown of the 2004-1 is not relevant to the thread.

I find it easiest to start from the back and work forward. This portion will show the TY2130. First the rotor is removed.

Then the two black screws for the autowinding bridge are removed, and carefully lift it off. After the autowinding bridge is removed, the Mainspring is let down, then the ratchet wheel, crown wheel, click and click spring are removed from the barrel bridge.

Now, the barrel bridge is removed. We can see the placement of the balance stop (hack) lever.

And then the train bridge comes off. Two views of the gear train.

Then the balance and pallet fork come off.

On the dial side, (this is the HZ6300) the minute train bridge is removed. The hour wheel, minute wheel, setting wheel, date corrector are removed.

Then the rest of the calendar mechanism can be removed along with the cannon pinion.

We mentioned the one loose spring in these movements, here it is, the click spring, along with the click and crown wheel.

Now that they are apart, we get some comparison shots and give a good hard look to the quality of these movements.
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Found something interesting already.

Here are comparison shots of the three mainplates, see if you can spot the one that is different.


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Apart from the plate finish colour and cap jewel clips the only thin I see is that the Hangzhou has several more holes in the plate than the other two.

Does it have more screws securing the plates?
The major difference is how how the bridges are aligned to the main plate. Here are detail shots of the differences. The Hangzhou and ETA use holes in the mainplate and trepanned studs on the bridges, the Seagull uses holes in the bridges and holes with pins in the mainplate. The Seagull uses the method favored by Selitta in the SW200, except for the balance bridge, where Seagull uses the ETA method.




Why do I find this interesting?

Putting pins in holes and controlling accuracy to a few hundredths of a millimeter is a hell of a lot easier than trepanning a stud, and saves material. The stock material for a trepanned stud must start out with sufficient material to allow for the stud to be cut out.

The Hangzhou also does have a few additional holes drilled in it, but all of these hole are non-functional, either pilot holes for a day/date mainplate, or additional holes for oiling and/or inspection.

One other thing that is not readily apparent in the long range shots above is the Seagull was completely devoid of any oil. The Hangzhou was well oiled.

Seagull jewels, no oil:

Hangzhou, note the oild bead on the jewels and the oil spread discoloring the plate:
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Its like many many years ago when Honda introduced CIVIC on US soils, How we treated like JUNK, The time has come not to underestimate the "GIANT"

Thanks for the photos and testing results. :-!
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Why does the Rado inscribed rotor on the 2824 declare 17 jewels? Should have 25 jewels if it's a 2824.
Why does the Rado inscribed rotor on the 2824 declare 17 jewels? Should have 25 jewels if it's a 2824.
The 2824-2 was available in 17 or 25 jewels (as was the 7750,) since then, ETA has discontinued offering 17 jewel versions of its mechanical automatics, all are 20 jewels or higher, except for maybe the 7-3/4 ligne lady's models.

You will see in the following posts, that the Rado does not have any jewels in the automatic winding system, this is where the additional eight jewels are located.
Before I go any further, if you what to see a particular part of either of the movements go ahead and ask now, as space constraints on my desk top may require these to be reassembled.

Part two: b) Comparison of Quality.

The easiest way to do this is line up the parts side by side and let you see what differences there are. All parts are laid out in the same manner, from left to right; Seagull, Hangzhou, ETA 2824. The 2004 parts are so different, as it is based on the 2892 architecture they are not included in the side-by-side comparison.

The pallet fork:



ETA 2824:

ETA 2004:

The two ETAs certainly use less shellac on the pallet stones. The Seagull seems to have allowed some bubbles as well.

Pallet and pallet bridge:

Balance and balance cock:

Escape wheel:




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What is the significance of the lack of oil in the SeaGull?
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Part two: b) Comparison of Quality (cont'd).

Train wheels:

Seagull center wheel:

Hangzhou center wheel:

ETA center wheel:

Close-up of the third wheel:

More 3rd wheels:





Barrel and train bridges:

Autowind bridge (disassembled):


Rotor center gear and bearing:




Date wheel:

Close-up of the Seagull autowind bridge rotor axle:

Same shot of the Hangzhou:

Just a shot of the same place on the underside of the three movements:



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Wow, the hole in the Seagull autowind bridge rotor axle is quite misaligned!
What is the significance of the lack of oil in the SeaGull?
A follow on to that, the balance pivots were oiled, more oil than I would have used, this fact and the fact that I have run across a fair number of Seagull movements, all oiled to some degree, leads me to conclude that this is a "quality escape."

What would be the consequence of not having any oil? Nothing you would notice immediately, accelerated wear and tear mostly.

But, on the bright side, it will never dry out and gum up on you. :-d

Over oiling will probably lead to more immediately noticeable problems.
Wow, the hole in the Seagull autowind bridge rotor axle is quite misaligned!
The problem with these image heavy posts is it is hard to keep track of all the things you are trying to show.

That is one reason why I posted it, but would you like to know why it is off center?

The rest of the story is told from the back side of the autowind bridge: (Seagull on the left, as usual, ETA not shown, as it is the same as the Hangzhou, except for three jewels)

Close-up, Seagull:

Close-up, Hangzhou:

The original design for the autowind bridge is that the rotor post be a separate part staked into the bridge. This was probably done so at some point the post could be removed (the autowind bridge design is shared with other movements without ball bearing rotor). However, the current application with only a ball bearing rotor and no relative motion the post, this is a superfluous requirement. So, Seagull simplified the design to eliminate one part and three manufacturing operations

Aside from the unsightlyness of the off-center hole, it really has no influence on the operation of the rotor, the screw that goes in the hole is only there to retain the inner bearing race.

And, just as a point of reference, although it looks huge in the picture the screw hole is only off-center by 0.044 mm (or 0.0017 inches, for US.)
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I'll bet the Hangzhou doesn't work when you reassemble it :-(

Maybe it's just my monitor but the Sea Gull looks to be better finished over all than either of the others and in some respects the Hangzhou even bearts out the ETA.
I also notice that the Sea Gull is much better finished than the one that was dissected over on TZ or that other forum.

When it comes to dropping your pants for an inspection; this expose really should have the ETA folks feeling nervous or litigous :oops:

So far, the only thing that worries me about the Sea Gull is the lack of lubrication...what's that all about???
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